1. Field of the Invention
The invention relates to one or more optical networking components. In particular, the invention relates to demultiplexers.
2. Background of the Invention
The wavelength division multiplexing technique allows a waveguide to carry more than one channel of information in a multichannel beam of light. Each channel is carried on a light signal having a unique wavelength.
A demultiplexer is typically employed to separate the channels in a multichannel beam. Separating the channels allows the channels to be independently processed. The demultiplexer receives the multichannel beam on an input waveguide and outputs each of the channels on a different output waveguide. Accordingly, each output waveguide is typically associated with a particular channel.
The intensity versus wavelength profile of the light in each output waveguide typically peaks at the wavelength associated with a particular channel. However, the wavelengths of light that appears on a particular output waveguide can shift. For instance, temperature changes can affect the index of refraction of materials in the demultiplexer. This change in the index of refraction can cause the wavelengths of light that appear on an output waveguide to shift. This shift can cause the intensity distribution seen on a particular output waveguide to shift away from the peak in the intensity versus wavelength profile. As a result, these shifts can a drop in the intensity of the signal in a particular output channel. This drop in the intensity is a source of optical loss in the optical network.
For the above reasons, there is a need for a demultiplexer that is not associated with optical losses that result from a shift in the wavelengths of light that are provided on a particular output waveguide.
The invention relates to a wavelength based optical component. The component includes a plurality of output waveguides and a light distribution component configured to focus a light signal on one of the output waveguides. The light distribution component focuses the light signal such that the light signal has a substantially flat top shaped intensity versus wavelength profile. In some instances, the light signal has a substantially square shaped intensity versus wavelength profile.
Another embodiment of the optical component includes an array of array waveguides. The optical component also includes a first light distribution component configured to distribute a first light signal to the array waveguides. The first light signal is distributed such that a fraction of the first light signal enters each array waveguide. Because the first light signal is divided over the array waveguides, at least a portion of the array waveguides each carry a light signal fraction. The optical component also includes a second light distribution component configured to receive the light signal fractions from the array waveguides. The light signal fractions are received so they combine to form a second light signal with a periodic intensity distribution.
Another embodiment of the optical component includes a second light distribution component and an array of array waveguides. Each array waveguide is configured to deliver a light signal fraction into the light distribution component such that the light signal fractions combine to form a light signal in the light distribution component. The light signal formed with a periodic intensity distribution.
Yet another embodiment of the optical component includes an array of array waveguides. Each array waveguide is configured to receive a fraction of a first light signal. The array waveguides are configured such that light signal fractions exiting the array waveguides combine to form a second light signal having a periodic intensity distribution. The optical component also includes a first light distribution component configured to distribute the first light signal to the array waveguides.
Still another embodiment of the optical component includes a light distribution component and an array waveguide grating having a plurality of array waveguides in optical communication with the light distribution component. The optical component also includes a plurality of attenuators. Each attenuator is configured to attenuate a light signal carried by one of the array waveguides.
A further embodiment of the optical component includes a light distribution component and an array waveguide grating having a plurality of array waveguides in optical communication with the light distribution component. At least a portion of the array waveguides have an inlet port and an outlet port with different cross sectional sizes.
The invention also relates to a method of operating an optical component. The method includes receiving a first light signal and converting the first light signal to a second light signal having a periodic intensity distribution.
In some instances, the periodic intensity distribution approximates a sinc function.